With some of the newer powders that Rocky Gibbs didn't have to work with the Gibbs rounds really come alive, especially with heavier bullets...check out my thread on Reloader 17 in the 8mm Gibbs. An honest 2894 feet per second with 185gr Rem PSPCL, a 22.5 inch tube and NO measurable signs of over pressure.
Reloader 17 8mm Gibbs 
